We've spent the last few days singing along to
Kat Graham's newest song from her upcoming album (she's
offering a free download!), so it's only fitting that tonight, Kat makes her triumphant return to
"The Vampire Diaries" after being MIA so far this season. (Yes, we know we saw her briefly in the premiere, but that was product placement, not plot development!) Move over, Chance Harbor witches... our girl is back on Thursday nights.

"Bonnie returns from summer with the normal side of the family," executive producer
Julie Plec tells us -- referring, of course, to the side of Bonnie's family that doesn't have a grimoire in every bathroom for some light reading. "Bonnie says 'Boy, summer with the normal side of my family is like watching paint dry,' and Caroline says, 'Well, I'd give a lot for a normal side of my family right now,' having what she's just been through."

While she's been away, Bonnie's boyfriend Jeremy (Steven R. McQueen) has been having some creepy visions. Bonnie brought him back to life after the Sheriff shot him last season, and as a consequence, he now sees the ghosts of his dead vampire girlfriends, Anna (Malese Jow) and Vicki (Kayla Ewell).

"I think they're here to fight for their existence," Kat told us when we visited her on set in Atlanta. "I don't think Bonnie's really part of their agenda. I think that they, from what I've see so far, come from a pretty pure place."

Not being a part of their mission doesn't mean that Bonnie won't be deeply involved in the ghost storyline. In particular, it will force her to examine her relationship with Jeremy on a deeper level.

"There is an agenda happening with our ghosts that isn't just 'Hey, I want to make amends with my loved ones,'" Julie confirms. "I think as we get into next episode and Bonnie's return and Jeremy holding this secret, [she is] this person that's been very easy to keep this secret from because she's been away. Now couple months have gone by and he hasn't 'fessed up to it, so at what point does it become not wanting to let her in on something, and at what point does it shift to an out-and-out lie?"

Julie says that the ghost girls will cause a significant rift in the relationship between Bonnie and Jeremy. "Over the next couple episodes, our arc is to see what the ghostly and supernatural consequences are of that."

"If he was like, 'Oh, I want them away,' I think that Bonnie would be compassionate towards him," Kat says. "But if he's like 'Well, I think I'm going to spend some time with some ghosts and I'll call you later,' I don't think she'd be cool with that."

In Jeremy's defense, of course, the girls died while he was still dating them. That lack of closure can take its toll on a kid. "I don't know one relationship where you end it and they're
alive and you have closure," Kat says. "At least I've never felt like I've had complete closure with anyone.... so already, how much can you get with a breakup? But if they never broke up and they just got ripped from you before you had the chance to fulfill that relationship, I doubt that he's got any form of closure."

Kat's not spilling about how Bonnie does feel about the ghosts, but she does make sure to point out that Bonnie can be rather unpredictable in tough situations. "I've seen Bonnie be super super compassionate at times where I'm like 'Are you serious?' I would've left town! And there are times where she's been really, really tough, almost to the point where she has to be pulled back. I.E. Damon fire."

Let's hope she keeps her gasoline to herself this time!

Despite the misery that seems to be constantly licking at these kids' heels, they're still looking to be teenagers and have a little fun their senior year. "They're going to try to find it," Kat says. "High school kids want to be high school kids and you want to find those moments in your life where you're like, 'This is fun.' Even in the crazy schedules that we have, as cast members we always find time to just get together and have fun, just be young adults, you know?"

Senior year brings on questions about the kids' future after Mystic Falls High (that is, if they have time to graduate with all the saving-the-town happening). "I think Bonnie and Elena are going to grow old together," she says. "Wherever they go, I think they go together."

Since the death of Bonnie's super-awesome grandmother, we haven't had much insight into Bonnie's home life or her family -- we've never even seen her room! We've read your comments, tweets, and emails, so we know that all of the Bonnie fans are anxiously awaiting a peek into Bonnie's background. Kat told us this summer that she's hoping to meet another family member of Bonnie's this year, but she's not too stressed about it.

In fact, while her castmates regularly tell us about their calls to the "Vampire Diaries" writers, Kat seems more laid back. "You know, when Kevin and Julie and I hang out, we don't talk about the show," she says. "If they bring it up it's cool, but I just like hanging out with them. I don't really ask them. If it happens and it develops, then it would be great. If not, I'm sure they've got some other great stuff planned. At the end of the day, I'm a hired actor, and I'm here to tell their story, not my own, or what I think should be Bonnie's story."

If you're wondering, folks -- Bonnie does not have a familial connection to Gloria the witch we met in last week's flashback episode. When asked about the show's tendency to hire African-American actors for the witch roles (with the exception of Maddox), Julie says, "The reason that seems like an ongoing element is because ultimately the show is about bloodlines and family and the roots of family that take us all the way back, all the way back, so for a lot of our witches there's actually been a family tie, and we'll continue to see a family tie. [However] in Gloria's case, Gloria was just really really cool and a great actress and had a great awesome attitude and we just really liked her and that's the choice that we made there."

Watch our video interview with Kat Graham below to hear about how much fun she's been having on set with Malese and Kayla, plus her thoughts on Bonnie possibly using her power for evil. Don't forget to tune in to "The Vampire Diaries" on Thursday at 8 p.m. EST on The CW!